iron boot vs iron heel

iron boot and iron heel both are nouns.

Word	Noun	Adjective	Verb	Adverb
iron boot	Yes	No	No	No
iron heel	Yes	No	No	No

As nouns, iron boot and iron heel are synonyms defined as:

iron boot and iron heel: an instrument of torture that is used to heat or crush the foot and leg

Other synonyms of iron boot include boot, the boot.

iron boot (noun)	iron heel (noun)
an instrument of torture that is used to heat or crush the foot and leg	an instrument of torture that is used to heat or crush the foot and leg